Much of the heat cars gain in the summer comes through the roof. An insulated reflector attached with magnets (or even glue) to the roof of a car reflects most of the heat away, and the insulation reduces the heat conducted through the roof.-- macrumpton, May 31 2004 In the same vein http://www.halfbakery.com/idea/Carbrella [DrCurry, Oct 04 2004, last modified Oct 05 2004] I'd bet more heat comes in through the windows than the roof.-- phoenix, May 31 2004 Actually I just got my car painted yellow, after having it black for 2 years and the temp difference is very noticeable. But I also have tinted windows, but so would anyone who lives in the south and does not want a 150° car in the summer.
Unlike the carbrella, my device would stay on the car even while being driven.-- macrumpton, May 31 2004 ups trucks employ such a panel, it's painted white. (+)-- xclamp, Jun 01 2004 Hmm... "Carberella". Now there's a pun just waiting to happen.-- lostdog, Jun 01 2004 random, halfbakery